This invention relates to cephaiosporin antibiotics, to pharmaceutical formulations comprising the antibiotics, and to a method for the treatment of infectious diseases in man and other animals.
Cephaiosporin antibiotics have the bicyclic ring system represented by the following formula wherein the numbering system is that commonly employed in the arbitrary cepham nomenclature system. ##STR3##
In the field of antibacterial therapy, the need for new chemotherapeutic agents is one that will never extinguish. Mutant strains resistant to existing antibacterial agents are encountered frequently. In particular many strains of Staph. aureus and Staph. epi (so-called methicillin resistant Staph. (MRS)) are becoming increasingly resistant to available antibacterial agents. (see, for example, Phillips, I., and Cookson, B., J. Appl. Bacteriology 67(6)1989). To meet this need, considerable research effort continues to focus on such new agents. The present invention provides antibacterial agents useful against a wide variety of gram-positive and gram-negative bacteria. The compounds cf the present invention are especially useful against these methicillin-resistant Staph. organisms.